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respectively. All the points were in zone C, with the
exclusion of points 10 and 13 in the first campaign
(Faraglioni and Levanzo, B zone) and 8 and 12 in the
second campaign (Faraglioni, B zone, and Marettimo, A
zone, respectively).
6DPSOLQJ
Water and sediment samples were collected in
September 2012 and September 2013, before the end
of summer, when boating activity is still intense and
the contamination from AF paints is expected to be
significant. Seawater was collected in all 25 sites; in 7
sites it was not possible to collect any sediments due to
the rocky bottom (4 in 2012 and 3 in 2013).
A Glass-Sampler Probe (International PBI, Milan, Italy)
was submerged to a depth of 0.5 m below the sea surface
and seawater samples were collected in pre-cleaned
1 l glass bottles. All the containers were additionally
rinsed with seawater before sample collection. The
aqueous samples for analysis of Monobutyltin (MBT),
Dibutyltin (DBT) and Tributyltin (TBT) were acidified
in situ with 0.8 ml 37% HCl per liter. The aqueous
samples for analysis of biocides compounds were
FIGURE 3 Passive sampler placement by scuba diver in Preveto site $QDO\VLV
32 EAI Energia, Ambiente e Innovazione 4/2015
added in situ with 2 ml of dichloromethane per liter.
All water samples were stored in a fridge at 4 °C until
the analysis.
Surface sediment samples were collected in 18 sites (9
in 2012 and 9 in 2013) by a stainless steel Van Veen grab
sampler. After collection, sediments were stored at -20
°C and then transported to ENEA laboratories, where
the sediments were sieved at 2 mm: the fraction <2 mm
was considered for analysis. After sieving, sediments
were freeze-dried.
Standard SPMDs (length 91.4 cm; width 2.5 cm; LDPE wall
thickness: 70–95 Ăm) with 1 ml of 99% purity triolein)
were purchased from ExposMeter AB, Tavelsjö, Sweden.
Before use, all the support devices were washed with tap
and distilled water before being rinsed with acetone
and hexane. The SPMDs were transported in sealed
clean metal cans and refrigerated at 4 °C. The SPMDs
were assembled with proper supports and inserted into
stainless steel cages (canisters, ExposMeter AB,Tavelsjö,
Sweden) on the boat just before the positioning. The
canisters were deployed between 1 to 6 meters below
the water surface and properly fixed to a buoy or to a
quay by a scuba diver (Figure 3). After retrieval, the
SPMD strips were immediately roughly cleaned with
acidic (HCl) water and stored at 4 °C in the metal can.
Biocides
500 ml of water were placed into a 1 l separatory
funnel, 50 ml of dichloromethane were added, and the
mixture was shaken for 2 min. The layers were allowed
to separate and the organic layer was filtered through
anhydrous sodium sulphate and collected in a round
bottom flask. Another 20 ml of dichloromethane were
added and the sample was extracted as above. The
extracts were reduced to approximately 0.5 ml on a
rotary evaporator and then transferred to a vial for GC-
MS analysis. [4].
To evaluate the recovery, samples of synthetic seawater
were spiked with biocides at two different levels: 10 and
100 ng/l. The samples were analyzed according to the
procedure described above. Four replicates of each
level were analyzed. The recovery values were greater
than 86% for both levels with a standard deviation of
9% in the most unfavorable case. LODs for this method
were 1 ng/l for all the biocides.